Electrical boxes often require the use of a mud ring or extension to position the electrical wiring device at the desired location with respect to the wall surface. The mud ring can have threaded screw holes to receive the mounting screws of the wiring device. Alternatively, the mud ring can have apertures that allow the screws to pass through to enable the screws to thread into the screw holes in the electrical box.
Various clips have been proposed that can be inserted into an aperture in a structure and have a passage for receiving a screw or other fastener. Many of these clips are made from spring steel.
For example, U.S. Patent Publication No. 2009/0087279 to McGinn et al. discloses a spring clip for connecting the screws of an electrical device to the cover plate of an electrical box. The spring clip can be connected directly to the inner face of the cover plate so the screw can slide through the opening in the spring clip.
U.S. Pat. No. 5,057,649 to Ring discloses an electrical wiring box with a tab and flange for mounting the electrical device. A spring clip is mounted to the outer surface of the flange for receiving the screws on the electrical device. The spring clip has inwardly extending legs to engage the threads on the screws.
U.S. Pat. No. 4,936,396 to Lockwood discloses an electrical box having inwardly extending columns with an aperture for receiving the screws of an electrical device. A spring clip is snapped into the opening. The spring clip includes legs with outwardly extending tabs to retain the spring clip in the aperture and inwardly extending tabs to engage the threads of the screw.
U.S. Pat. No. 7,568,870 to Paquet discloses a push nut that is received in the opening of a plate. The push nut includes an axial passage with inwardly extending legs for receiving the threads of a screw. Outwardly extending legs project outwardly to engage the inner surface of the plate and to couple the push nut to the plate.
U.S. Pat. No. 7,468,486 to Yan relates to an adjustable mud ring system. The device includes a frame attached to the electrical box and a movable extending member. The extending member has tabs with threaded holes so that an electrical receptacle can be attached directly to the tabs.
While these devices are generally suitable for the intended purpose, there is a continuing need in the industry for improved devices for attaching an electrical wiring device to an electrical box.